The present invention relates to the preparation of mono and di-hydroxyfluoroalkanes starting from the corresponding iodofluoroalkanes.
According to known processes for the synthesis of fluoroalkanols of the above-mentioned type which start from the corresponding iodides, for example oleum is used as a hydrolizing agent (U.S. Pat. No. 3,283,012). In this case there is the serious drawback of the removal of a considerable excess of H.sub.2 SO.sub.4 ; furthermore, the recovery of iodine is complex and by-products such as ethers or olefins ca easily form.
A later process (DOS No. 3,016,571) is based on a reaction in a two-phase liquid system, comprising a phase transfer catalyst and/or perfluorocarboxylic surfactants, the process comprising the step of reacting fluoroiodoalkanes with stoichiometric amounts of salts of Cu, Ag, Hg or with an excess thereof.
Some drawbacks of this method are the possible forming of emulsions difficult to be treated, the use of high amounts of the abovesaid salts which must then be recovered, as well as of expensive ingredients such as the phase transfer catalysts.
A further patent (DOS No. 3,035,641) claims a process for the preparation of alkanols by means of a reaction between iodides and peroxyacids, the alkanols yield being equal to 86.5%.